Taste is absolutely linked with temperature. Cold vs hot coffee for example. Don’t know exactly why. Most things tend to taste “more” when hot. Could be the intensity of molecular activity, which is what temperature is, that varies and so registers more or less strongly with our taste preceptors

This can be more readily observed with food IMO. Hot pizza tastes way better than cold pizza (though, of course, cold pizza still tastes great)

I'd guess much of this difference is also due to the fats in the cheese & meats solidifying at cold temperatures, and thus less readily coating taste receptors.

Or why kids tend to let their ice cream melt into “soup”, it tastes sweeter when warm

it makes sense to me that the chemistry of taste would be very sensitive to temperature. but often, heated water has more substances in solution

I'd expect it has less. Usually minerals accumulate in the water heater.

A lot of things at play.

1) We actually can sense "coldness" or "hotness" as separate tastes. Think about mint candies or pepper for example.

2) Our receptors have different sensitivity based on the temperature. For example cold sweet drink feels much less sweet. That's why warm cola is disgustingly sweet for example.

And water does contain a lot of dissolved salts which have a taste.

3) More than half of the taste we feel is actually coming from the smell, and warm water contains more vapour, and therefore, more smell.

So our brain takes all these inputs from different sources and synthesises the feeling of taste in our brain.

Source of this knowledge is from: https://www.cookingforgeeks.com

I would imagine it has with the biomechanics of our tongue as it relates to available dissolved minerals.

Just look at the inside of any water heater. Usually disgusting! This is why we heat cold water up when we cook, rather than start with hot water